STRIKER John Hartson is on track to spearhead the crucial stages of Wales' challenge for a place in next summer's European Championship finals in Portugal.

STRIKER John Hartson is on track to spearhead the crucial stages of Wales' challenge for a place in next summer's European Championship finals in Portugal.

The Celtic front-man was yesterday given the go-ahead to step up his rehabilitation following back surgery last month, which ruled him out of manager Mark Hughes' squad for the recent trip to the United States.

And he could be back in full training as early as the end of July, well before the new Scottish Premier League season gets under way.

That ' s good news for Celtic boss, Martin O'Neill and for Wales, who resume their Euro 2004 qualifying programme against Serbia-Montenegro in Belgrade on August 20, following that with an early September double-header against Italy and Finland.

The 28-year-old striker plays a key role in the 4-5-1 system which has brought Wales maximum points from their opening four Group Nine matches and he has scored a goal in all but one of them, only failing to find the net in the 2-1 win over Italy in Cardiff last October.

The back injury, involving a damaged disc in his spine, caused Hartson to miss out on Celtic's Uefa Cup final appearance against Portuguese side FC Porto, which was a huge personal disappointment following his decisive semi-final goal against Liverpool at Anfield.

Hartson visited a specialist yesterday to be told he had made excellent progress in the four weeks since his operation and could now begin a combination of gym and outdoor work.

Celtic are due to fly to Sweden next Friday for a short pre-season workout but Hartson is expected to remain in Glasgow to work on his fitness.

He has already returned to the gym following a family holiday and has also added cycling and swimming to his regime.

If his recovery schedule goes to plan, he will be able to rejoin his team-mates on the training pitch in early August and Hughes will be keeping his fingers crossed that his preferred target-man does not suffer any setbacks.

Only two weeks ago the Wales boss told the Daily Post he was closely monitoring Hartson's situation and was optimistic he would be back in action by the time he names his squad for the trip to Belgrade.